Overheating D4

GrahamHR said:
Thanks for the diagram. Am I right in assuming there's a hose going from that fitting to the transom shield? ( I am very familiar with the DPS drives, much less so with the DPH).
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Yes and if above 2500rpm's means the water clears the area around #3 then I would say that's likely your issue.
 
GrahamHR said:
The boat had not seen saltwater until 2014.

Bellows and oil change in late 2014 by VP dealer. Not used subsequently in 2014. About 35 hours use since then so to get it serviced again in 2015 and 2016 seemed excessive. Pre the 2015 and 2016 season I did of course check for oil leaks, milkiness in oil, bellows condition etc..

New aluminium anodes for the 2015 season ( plus electronic corrosion protection system) . Electrical continuity between all components checked pre launch and OK. Normal protection indicated by ACP control box. No corrosion on drive on lift out

New aluminium anodes for the 2016 season Continuity pre launch OK. Normal protection level indicated by ACP box.

What are these elbows made of, that causes them corrode away ? Are they not in electrical contact with the rest of the drive and protected ?
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They are made out of plastic, and they just crack (movement fatigue, I imagine).

I thought aluminium anodes were for fresh water?
 
jimmy_the_builder said:
They are made out of plastic, and they just crack (movement fatigue, I imagine).

I thought aluminium anodes were for fresh water?
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Aluminium are for both fresh and salt: magnesium for freshwater .I was very sceptical about aluminium anodes, but they work well it seems. More active metal atoms per unit volume apparently compared to zinc. Certainly in the first season with zinc anodes the ACP system was working at maximum capacity; since switching to aluminium, it's worikng a lot less hard to protect the outdrive.

I checked the impeller today. it's fine to it looks like a lift out needed. No point in putting it back in this season. The plastic water pipe connector on my last DPS lasted 9+ years without failure; it was a straight coupler though and the hose took all the up/ down and port/ starboard forces. Inevitable a right angle plastic elbow will fail when subjected to sideways/ up and down forces.

Failing after such a few operating hours ( and consequentially few cycles) without warning these parts seem to be a acting like a disposable yearly service item !
 
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DPS drive is a totally different set up yo your DPH , if you have the early drive you have the suspect early elbow, I carry 2 in the van all the time as there an overheat participant if they have never been changed since new. I tend to find you get air bubbles in the strainers at full chat before overheats , taking into consideration you have the latest strained lid mod .
Remember all Volvo owners are a live test bed for the guys in Sweden , you give them the problems and they eventually come up with an answer.
I suppose it's a bit like the NHS but they seem to run out if money first.
 
GrahamHR said:
Aluminium are for both fresh and salt: magnesium for freshwater .I was very sceptical about aluminium anodes, but they work well it seems. More active metal atoms per unit volume apparently compared to zinc. Certainly in the first season with zinc anodes the ACP system was working at maximum capacity; since switching to aluminium, it's worikng a lot less hard to protect the outdrive.

I checked the impeller today. it's fine to it looks like a lift out needed. No point in putting it back in this season. The plastic water pipe connector on my last DPS lasted 9+ years without failure; it was a straight coupler though and the hose took all the up/ down and port/ starboard forces. Inevitable a right angle plastic elbow will fail when subjected to sideways/ up and down forces.

Failing after such a few operating hours ( and consequentially few cycles) without warning these parts seem to be a acting like a disposable yearly service item !
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Interesting about the aluminium anodes. How often do you have to change them?

On the water pickup elbow - down here in France, the local VP tech told me they change them as a service item every two years. Seems like a crap bit of design to me.
 
jimmy_the_builder said:
Interesting about the aluminium anodes. How often do you have to change them?

On the water pickup elbow - down here in France, the local VP tech told me they change them as a service item every two years. Seems like a crap bit of design to me.
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I have changed thealuminium anodes every year; to be honest though there was well more than 50% left. I changed them "just in case". A small price compared to potential damage.

As to the elbow, "Seems like a crap bit of design to me" sums it up nicely !
 
volvopaul said:
DPS drive is a totally different set up yo your DPH , if you have the early drive you have the suspect early elbow, I carry 2 in the van all the time as there an overheat participant if they have never been changed since new. I tend to find you get air bubbles in the strainers at full chat before overheats , taking into consideration you have the latest strained lid mod .
Remember all Volvo owners are a live test bed for the guys in Sweden , you give them the problems and they eventually come up with an answer.
I suppose it's a bit like the NHS but they seem to run out if money first.
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Is there an improved elbow available for the earlier drives ( mine is a 2009 boat, the drive probably made in 2008.
 
GrahamHR said:
Is there an improved elbow available for the earlier drives ( mine is a 2009 boat, the drive probably made in 2008.
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I don't believe so. The part number is not showing as superceded. Of course, we don't yet know if this is your problem, or if there is some other issue causing your overheat.
 
jimmy_the_builder said:
Ah I didn't know that, thanks. The only ones I've seen have fins on them, so I guess are the later design. They fail in the same way!
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That's reassuring ! I can see me changing it every 2 years in future ( cheaper than anodes I suppose !). What song was it that had lyrics something like goodbye to the old boss, new boss just the same ?
 
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On early strainers the insert does not always go all the way down so when you tighten the lid, it is still sucking air. Try to jiggle the insert so it really hits the bottom if you suspect this....

Edit; I now saw that you have the pump before the strainer, then it is not this problem with air. I have it the other way on a boat.
 
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jimmy_the_builder said:
Ah I didn't know that, thanks. The only ones I've seen have fins on them, so I guess are the later design. They fail in the same way!
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As a matter of interest what colour are these elbows ? I ask because I found small pieces of a hard white plastic in the strainer and one piece in the water pump.
 
Update. The elbow was the type with ribs on it : it was undamaged but I changed it anyway. What had happened was that the rubber hose had come off it ( the clamp was tight, but in the wrong place !). Presumably the hose would have been taken off the elbow the last time the drive bellows was changed. I changed the impeller as well, though it looked OK.
 
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